1. Field of the Invention
The present invention relates to a pallet changer for changing pallets, on which workpieces are placed, and feeding the workpiece to a table of a machine tool and also relates to the machine tool provided with the pallet changer.
2. Description of the Related Art
For example, Japanese Utility Model Application Laid-Open No. 7-3938 discloses a pallet changer for a machine tool. The pallet changer may automatically discharge a pallet mounted on the table in the machine tool such as a machining center and may automatically feed a next pallet onto the table.
The pallet changer is provided with a base disposed in the vicinity of the table, a reciprocating base which may be moved to-and-fro on the base, a swivel shaft arranged, to be able to swivel about a vertical axis, on the reciprocating base and a swivel arm. The swivel arm has a size, such that two pallets may be placed thereon, and is supported by the swivel shaft movably in the moving direction of the reciprocating base and is swiveled together with the swivel shaft.
However, in the pallet changer described in the above-described Japanese Utility Model Application Laid-Open No. 7-3938, the reciprocating base has to move to-and-fro in the horizontal direction and to make a linear motion when the pallets are to be changed. Accordingly, the time for changing the pallets is likely to be prolonged, and also, there is a tendency that the pallet changer becomes complicated and the overall apparatus would be enlarged.